One Choice Can Save You
by Alexx18
Summary: Three years have passed since Tris' death. Tobias' memories of Tris are no longer so painful; he can look back on them with happiness. He misses her, but he knows there's no way to get her back. That is, until Caleb tells him otherwise. After three years of endless work, Caleb has perfected the Erudite time travel formula. Can Tobias travel in time to save the love of his life?
1. The End of Monotony

"_She didn't survive. I'm so sorry."_

For over a year, I could still hear Cara's voice saying this to me. Every morning when I woke up, that was the first thing I thought of. Then, the other memories followed.

Tris' lifeless body lying in front of me as I yearned for eyes to open again. Listening to Christina lecture me out of taking the memory serum. Tris' blond hair blowing behind her as she jumped on to the train. Tris' hands running down my spine as she kissed me. Tris' cremation.

Ashes. That's all that was left of her.

Some mornings, I'd cry. Sometimes I'd get sick thinking about all of it. Other times, I'd scream into my pillow until my head hurt.

No matter what I did, the pain would never subside. Sure, sometimes it would be less sharp. The stabbing pain in my heart would morph into a dull ache for a short amount of time. However, it only took one more memory to increase the pain once again.

It was like that for a long time. I didn't think it would ever get better. Thankfully, I had people to help me through it, people who were grieving as much as I was. Johanna gave me a job. Christina gave me a friend. My mother gave me strength.

I definitely hadn't completely healed; I doubted I ever would. Three years had passed, and I still didn't go a single day without thinking about her. I still loved her, and I doubted I could ever love anyone again. I couldn't imagine sharing what I did with her with anyone else. It was getting easier, though. My memories of Tris didn't sting nearly as much as they used to. They brought me happiness. I knew she was watching over me, and I knew I could live a good life. She'd be happy for me.

I was spending a normal, monotonous Monday in my office going through paperwork when an unlikely person changed my life. I was very focused on my paperwork, so I did not notice someone standing in the doorway. He cleared his throat, and I looked up at him.

It was Caleb.

"Hi," he said.

I nodded at him. I hadn't seen him since we scattered Tris' ashes about six months ago. He didn't look much different, but there was something strange about him that I couldn't put a finger on.

"I was wondering if I could talk to you about something. I know you're working right now, but I assume you get off soon?" he asked.

I looked at my watch. It was 4:00pm. One more hour.

"Yeah, almost. Is everything alright?" I asked.

Caleb looked…shaky. It was almost as if he'd seen a ghost.

"No. I mean, well, yes. Things could be…amazing. But I just…I don't know," he said.

I stood up to get a better look at Tris' brother. His hair was standing up all over the place, he had large, dark circles under his eyes, and his face was very pale. There was something very wrong. But what? Why did he need me?

"You know what, I can pick up where I left off on this stuff tomorrow. Where should we go to talk?"

"I live right down the street if you wouldn't mind stopping by my place. This needs to be private," said Caleb.

"Sure," I said, and I followed him out the door.

I had never been to Caleb's apartment before. We weren't exactly close. It was still hard to be around him for too long without being too reminded of Tris. Today, however, he barely even looked like Caleb.

When we made it to his apartment, Caleb immediately shut and locked the door behind him. I opened my mouth to ask him what was going on, but he beat me to it.

"We can save her," he gasped the words as if they'd been fighting their way out this whole time.

"I'm sorry?" I asked, utterly confused.

"Tris. We can bring her back."

I blinked at him. At first I was angry because of this cruel joke he was playing on me. Then I was sad, because I knew he must miss her, too. Maybe. I still questioned Caleb's morals to this day. Eventually I reached a solid conclusion: he had to be on drugs.

"Caleb, what are you on?" I asked him with a sigh.

The exasperated look on Caleb's face changed. It became very serious, and he looked as if he may punch me. I stayed on my toes just in case.

"This isn't a joke, Four. I've been working at this for almost three years. There's a way. The Erudite were working on this project for decades, and I think I've finally cracked it. I'm still trying to get the timing and location logistics right, but I really think I have it this time."

I was still extremely confused, but I couldn't stop the odd, hopeful feeling forming in my stomach.

No. _No. _She was gone. She was gone and there was absolutely nothing I could do about it.

"Caleb, I don't have a clue what you're talking about, but – "

"Time travel, Four. Time travel! I can send you back to the day she died, and you can save her!" he shouted.

I stared at him. He had to be out of his mind. Of course I'd heard of time travel. It was something people dreamed and fantasized about it. It was fictional. It wasn't real. It wasn't possible.

"That's impossible, Caleb. I think I'm going to leave."

I headed toward the door, but Caleb shouted, "Wait!"

I turned around and watched him dig through his bag and pull out a thick file folder. He handed it to me.

"Look through this. It's all of the Erudite research and formulas. It outlines all of the tests, trials, and results. They were getting so close, they just needed to push a little further. I'd imagine Jeanine slowed that down a little. This wasn't the only project placed on hold to make way for her other antics."

I chose not to point out how quick he was to assist Jeanine with her "antics," and took the file folder from him. The documents inside did look rather official. There were pages and pages full of mathematical formulas, there were pictures of machinery and compounds, there were diagrams of the human brain, and a ton of scientific journals written by people who must have been some of the smartest people to walk the Earth.

"That's only a fraction of the work that's been done on this project, and I've completed it. I just know I have. It works. It really works and we can _save _her!"

I looked up at Caleb. The hopeful feeling in my stomach was on its way back. It had been three years since I'd lost her. I guess he lost her, too. He hadn't given up. He worked for three years to try and find a way to bring her back. Could I really see her again? My hands began to shake slightly, and I handed the folder back to Caleb.

"Do you really think it will work?" I practically whispered.

"Yes. I tested it. I can show you," said Caleb.

I looked directly into his eyes. I was always good at knowing when people were lying to me.

"Show me."


	2. Time

"This is the chamber," said Caleb, gesturing to the device that was supposed to send me back in time.

We were in a lab in what used to be the Erudite headquarters. Just being there gave me the chills. The chamber Caleb was showing me was made completely of steel, and the door looked extremely heavy. It was centered in the middle of the room and had numerous wires, poles, and pipes connected to it.

Caleb walked away from the chamber and stood behind a large control desk with several computers mounted on top of it. There was no desk space to be seen. Every inch of it was covered in keyboards, mice, clipboards, pens, graphs, and charts.

"This is where the actual magic happens though. From here, I can conduct he actual time travel sequence. Each one of these computers has a different function. It creates a sort of wormhole in order to send you back. It's a combination of gravity and speed…but it's so much more than that."

Caleb was looking at the chamber as if he were in love with it. He struck me as someone who would never be able to look at a person that way.

"You said you could show me," I said.

I didn't like that he was already talking about "sending me back." I was still rather skeptical about the whole thing. There's no way any of this could actually work.

Caleb nodded and marched across the room until he opened a door I hadn't noticed before. He reappeared seconds later with a cage in his hand. There was a canary inside.

"A few hours ago, I killed this bird's brother. I lured it out with this," he held up a small, strange-looking device, "It has a treat inside, so naturally the canary comes out to get it. However," Caleb stuck a pen into the opening of the device, and it clamped shut, snapping the pen in half, "That's what happened to the bird's head when he reached for his treat."

I frowned. I didn't understand how animal cruelty was going to show me anything.

"We're about to send this bird back in time, and there's a 90% chance that his brother will be joining us here shortly after."

I just looked at him. Caleb rolled his eyes.

"This bird knows that it's really a trap. Canaries are smart. They don't make the same mistake twice. He will go back and be with his brother. He won't understand why, but he'll know that when this trap comes along, they cannot fall for it."

I nodded slowly and said, "Why do you say there's only a 90% chance?" 

Caleb shrugged and said, "He could fail. He could hate his brother. His brother could hate him. There are a number of things that could change the outcome. But when I ran tests with multiple species, the average was 90%."

I felt a little sick at the thought of Caleb locked up in his lab, killing animals and seeing how many came back to life.

"So, let's send this little guy back," said Caleb.

He typed in a code next to the door of the chamber, and I could hear the sound of huge locks unlatching themselves. The door slowly swung open, and Caleb let the bird into the chamber. I continued to watch as he shut the door again, locked it, and raced excitedly behind his control desk. He placed the now empty birdcage on the ground and began his work.

"You can come over here and watch if you'd like," he said as he began to type furiously on multiple keyboards.

I walked slowly behind him and watched as the screens of the monitors changed. The lab became extremely loud as the machine powered on. Caleb shouted over the noise to try and explain to me what he was doing.

I'm not an idiot. I actually like to think I'm pretty smart. But this stuff was just beyond me. So, I simply nodded along and pretended to make sense of what he was saying.

"The sequence will begin now!" Caleb shouted after about ten minutes.

The chamber rumbled even louder, and I fought the urge to cover my ears. The room began to shake slightly, and I looked around nervously. Caleb didn't seem to be phased. He watched happily as the graphs and charters on his monitors convulsed and fluctuated.

Finally, after another five minutes or so, the noise stopped. Caleb began typing again, and I suddenly heard chirping behind me. I turned around and saw the cage Caleb had placed on the ground. Two canaries were chirping together happily.

I looked at Caleb, who was watching me with a smirk on his face.

"Where…where did those come from?" I gasped.

Caleb turned away from me and walked toward the chamber. He opened the door and gestured for me to look inside. I followed him. There was definitely not a canary in there.

"So…the bird that was in here…is over there now? In the cage?"

"Exactly," said Caleb, looking pleased.

"With his brother?"

Caleb nodded.

I took a deep, shaky breath. This was insane.

"I understand that it's a lot to take in. It's really quite extraordinary. But this is how we can save her. She can be with us again," he said excitedly.

Her. Tris. My Tris.

"Why do you even care?" I asked, suddenly angry, "You let her die, and that wasn't the first time you stood by waiting for it to happen. You didn't care about her. Why now?"

Caleb's pleased expression disappeared. He looked at the ground and said, "She told me she loved me. Before she died, she told me that she loved me and that she didn't want to leave you. We were the last two people she thought about, and I didn't do anything to deserve that. You did."

I didn't say anything, and Caleb continued.

"That's why I'm not the one going back. It has to be you. You can save her, I can't. I'm not good enough. This is the best way I can help. This is the best way I can try and deserve her love."

Caleb looked away from the ground and back at me. His eyes were filled with tears, and I could see that he wasn't lying. He didn't understand what he was always doing wrong. He didn't understand anything that wasn't math or science. He didn't understand feelings. He would always be an Erudite through and through.

"I know you want her back. I know you want to be with her again, and I know you're the only one who can save her," said Caleb.

"Alright," I said quietly, "I'll do it."

Caleb breathed a sigh of relief and said, "Thank you. There are some things you need to know before you do this."

"Let's hear it," I responded.

"I don't really know what will happen next. After I send you, you're on your own. You can't come back here. Once you're in the past, that will be your new present day. Does that make sense?"

"I think so," I said.

"You and I are the only ones who will know what really happened, unless of course you choose to share it with Tris. I highly discourage you from doing that, though. That could get messy, and you wouldn't have much time – "

"I'm not an idiot," I said, "I'm not going to do anything stupid. Am I…Am I really going to get to be with Tris again?"

Caleb nodded and said, "Yes, if you succeed. Otherwise – "

"I have to deal with her death all over again."

"Correct. If you fail, I have no way of bringing you back. You'll have to face the new reality that you create for yourself – good or bad," said Caleb.

I nodded and looked at the machine.

"Alright. Let's do this," I said.

"Now?" asked Caleb. He seemed a little surprised.

"Now or never," I said.

I really had to do it right then. I feared that if I left that lab, my fear would keep me from ever entering it again. I really was terrified. I was scared of seeing Tris again, scared of failing, scared of what that awful machine was going to do to me. But I had to try. I had to save her. I would do anything to save her.

Caleb nodded and turned to the chamber. He unlocked the door and backed away to let me step in. I walked in slowly. It was slightly larger than an elevator. The walls, floor, and ceiling were white. I could see vents and small openings where the multiple pipes I saw earlier must lead.

"As I said earlier today, I'm still having some trouble with the exact time and location," said Caleb, "I should be able to get you to the compound around when Tris was killed, but it may be a little earlier than the day of her death. I figure it's better to get you there too soon than too late."

I nodded. My mouth had become very dry. My heart was beating fast. My palms were sweaty. I was terrified.

"Remember, no one will know but you. You're going to have to do everything you can to act just as you would have that day. Don't try to change too much, it'll set everything out of balance. Just save Tris. Focus on that action alone, and act as you would have then. Understand?"

Caleb's was face was very serious. This was extremely important to him. He was depending on me to save his sister. It was the only way he could even come close to redeeming himself.

"Yes," I practically whispered.

Caleb nodded at me and reached out to shake my head. I reached out and shook it.

"Good luck," he said.

"Thanks."

Caleb smiled at me and shut the door of the chamber, enclosing me in complete darkness. I was breathing very fast. I could hear the machine turn on, and I discovered that the noise was even louder from within the chamber than it was in the lab. Not having to worry about Caleb mocking me, I covered my ears. It barely made a difference.

I stood like that for what must have been close to ten minutes, when suddenly the noise became even harder to handle. The chamber began to vibrate, and I found it very difficult to stay standing. Seconds later, I felt like my body was being compressed from all sides. My claustrophobia kicked in, and I tried to thrust my arms out to stop the walls from caving in, but they touched nothing. The walls weren't moving.

My body was covered in cold sweat, and I was struggling to breathe. I felt l some kind of wind hit me, and it gave me the chills. What ever was compressing me squeezed harder, and it took and extraordinary amount of effort to continue breathing. I tried to move, but I couldn't anymore. Suddenly, I had no control over my limbs. I couldn't even make my toes move. Just when I felt like I didn't have the energy to breathe anymore, it stopped.

I opened my eyes. I hadn't even realized they were closed. A gray blur flashed before my eyes. I blinked.

I stood before a large, sturdy net. It was strong enough to catch anyone, even if they jumped off a building to reach it. There was a girl lying in front of me, just an arm's length away. She was covering her face with her hands, but I could just barely see her smile of relief.

I couldn't see her eyes, not yet. But I could see the gray Abnegation clothing that swallowed her. I could see her blond hair tied back in to a tight, Abnegation bun. I knew who this was.

The girl moved her hands away from her face and I immediately reached out to her.

Tris.


End file.
